Community Forums

Cincy22EC · 03-16-2025, 03:41 PM

Might be the first with a possible DEF head failure on a 2024 Entegra Cornerstone?

16k miles and a warning saying "DEF Contaminated" came on an hour from returning home. 2/3+ of a tank with recent fill up with Walmart DEF. Checked DEF with refractometer and it appears right on the 32.5% mark. Spartan said if the quality does not show bad then its a "sensor" that only a Cummins place can pull the codes for. No other codes were showing.

Is this the new way of showing a DEF head failure? I know previously there would be 3 separate codes and a derate but I recall reading that newer coaches could still be driven.

If not a DEF head, what other sensor would it be? Taking it to Cummins as soon as I can after a call in the morning.

tom chelbana · 03-20-2025, 12:04 AM

When we travel the last thing you want is to have your trip interrupted with a know problem like a DEF head. We have a 18 LA with the Spartan chassis with 60K miles on it. About 6 months ago we had the 3 codes come up on dash and stated getting derated. We were 100 miles from any service assistance on a Saturday sfternoon. We couldn't get even a tow till Monday. Thank goodness we had purchased a extra DEF head 5 years before when DEF problem was reallu going. Installed DEF head which was 2 hours instead of 2 or 3 days later back on the road.
ALL DISIEL OWNERS WITH 2016 ENGINES NEED TO TRAVEL WITH EITHER A EXTRA DEF HEAD OR DEF SIMULATER. iT'S THE ONLY WAY TO KEEP ON SAFELY USE YOUR COACH.

WESCO · 04-13-2025, 06:51 PM

I carry a simulator. 5 minutes to plug in and you can make a repair at your convenience. I built mine as soon as I got a coach requiring DEF.

NCRog · 04-21-2025, 09:04 AM

Did the OP get this resolved? I had a similar set of warnings on my 2023 Essex, also a K3 chassis. See my exploits here: https://www.irv2.com/forums/f25/def-...rt-660293.html

With over 1,000 miles on the replacement DEF head, it appears to be working OK, no further alerts ... except an "Emissions" alert which comes on briefly when I start up. We've done several multi hour runs and I'm constantly watching for the dreaded contaminated alert!

I don't know what the failure progresses to ... I got multiple knee-jerk reactions from various service types. These ranged from total doom and gloom, I should prepare to go into limp mode at any time, to optimism that it cleared up each morning. However, with this being my second event (one each on both our '17 and '23 Essex coaches), I'm done with all the schedule disruptions and impact to our plans, I purchased a simulator. If it happens again I will make an assessment on how to resolve and get myself to a place which doesn't make me wait months for a service appointment ... because I didn't purchase from them.